The present invention relates to a magnetic film having the magnetic anisotropy, and in particular, to a control method for controlling the magnetic anisotropy and a device utilizing the magnetic anisotropy induced by use of the control method.
Among the methods for controlling the magnetic anisotropy in a magnetic film by using a magnetic field externally applied thereto, there are utilized in-field evaporation, a magnetic annealing and quenching effect, and a magnetic annealing or heat treatment (Neel and Taniguchi; J. Phys. Radium 15 (1954), 225).
In these methods, a magnetic film is subjected to the evaporation or magnetic annealing effect in order to control such properties along a direction of an applied magnetic field (spontaneous magnetization), i.e. a specific direction, as the ordering of atoms having magnetization in the magnetic film, selective growth of precipitated atoms, and selective growth at crystal transformation, thereby inducing the magnetic anisotropy.
These well-known methods, however, induce the magnetic anisotropy by externally applying a magnetic field to a magnetic film in a range which allows diffusion of atoms in the film due to thermal energy. Consequently, it is impossible, for example, to control the magnetic anisotropy only in a desired limited portion of the film along an arbitrary direction. That is, abovementioned methods have a disadvantage that the magnetic anisotropy of the entire magnetic film is induced only along a specific direction of the applied magnetic field. In addition, as can be seen in a magnetic annealing or heat treatment, for example, a considerably long period of time and a great amount of thermal energy are required to realize a desired magnetic anisotropy by use of the thermal diffusion of atoms.